I had one w/ 2 fh and a bunch of other fish for a while (wouldnt recomend for most fh though -thier just too mean) but the male in mine was very very mellow
I have lost a couple female flowerhorns and one male trying to have them in a 125g community tank, so great job I did not think it could be done. I keep mine by them self except for breeding them now. Did you raise them togeather? How many in the tank? Do they fight much?
The only type of "Community" tank, if you could call, that I heard of with a FH was one that shared a tank with an armored cat. the FH would try an eat it but couldn't get past the armor, thats the only reason it worked.
generally fh are territorial and very aggressive so they can't be grown in community. growout unitil 3-4 inches maybe but would eventually bite each other to death